1. Field of the Invention
The present invention is directed to an optical visual field-expanding system (FES) capable of obtaining a larger field of view than is possible with conventional optical instruments.
2. Discussion of the Background
A wide field of view, conventional optics, prismatic binocular set (e.g. 7.times.35) has a typical field of view of 500 feet at 1000 yards. Similarly, wearable low-vision telescopes that are currently available have fields of view of no more than 12 to 15 degrees at magnifications of 3.times. to 4.times..
Therefore, it would be beneficial if the field of view in these conventional optic binoculars and telescopes could be expanded.
It has been known in the art to utilize optical scanning systems for scanning a wide incoming field of view as disclosed in U.S. Pat. No. 4,788,423 to Kline. This reference teaches utilizing two rotating mirrors which are synchronized and direct a scanned image onto a sensor with minimal rotation and distortion of the image. However, such a scanning system has not been known which can give adequate field expansion and which can be employed in a binocular or telescope where the image is reflected onto the retina of a viewer.
In an optical system where an image impinges onto the retia of a viewer, the viewer is prevented from maintaining a wide field of view due to the size of the exit pupil of the eye piece lens of the optical system or of the entrance pupil of the eye.